<?php
/* 
 *  验证码类库
 *  调用类库方式如下
 *  $code=new NumForChek();
    $code->doimg();
 *  
 *  
 *  */
class NumForChek
{

    private $charset = '123456789';//abcdefghkmnprstuvwxyzABCDEFGHKMNPRSTUVWXYZ23456789
 // 随机因子
    private $code;
 // 验证码
    private $codelen = 4;
 // 验证码长度
    private $width = 130;
 // 宽度
    private $height = 42;
 // 高度
    private $img;
 // 图形资源句柄
    private $font;
 // 指定的字体
    private $fontsize =40;
 // 指定字体大小
    private $fontcolor;
 // 指定字体颜色
                        // 构造方法初始化
    public function __construct($width=null,$height=null,$fontsize=null)
    {
        
        $width?$this->width=$width:'';
        $height?$this->height=$height:'';
        $fontsize?$this->fontsize=$fontsize:'';
       
        
        $this->font = './elephant.otf'; // 注意字体路径要写对，否则显示不了图片
    }
    // 生成随机码
    private function createCode()
    {
        $_len = strlen($this->charset) - 1;
        for ($i = 0; $i < $this->codelen; $i ++) {
            $this->code .= $this->charset[mt_rand(0, $_len)];
        }
        //echo $this->code;
    }
    // 生成背景
    private function createBg()
    {
        $this->img = imagecreatetruecolor($this->width, $this->height);
      //  $color = imagecolorallocate($this->img, mt_rand(157, 255), mt_rand(157, 255), mt_rand(157, 255));
        $color = imagecolorallocate($this->img,255,255,255);
        imagefilledrectangle($this->img, 0, $this->height, $this->width, 0, $color);
    }
    // 生成文字
    private function createFont()
    {
        $_x = $this->width / $this->codelen;

        for ($i = 0; $i < $this->codelen; $i ++) {
            $fors=40+$i*15;
            $this->fontcolor = imagecolorallocate($this->img, mt_rand(0, 156), mt_rand(0, 156), mt_rand(0, 156));
            imagestring($this->img,$this->fontsize,$fors,18,$this->code[$i],$this->fontcolor);
        }
    }
    // 生成线条、雪花
    private function createLine()
    {
        // 线条
        for ($i = 0; $i < 6; $i ++) {
            $color = imagecolorallocate($this->img, mt_rand(0, 156), mt_rand(0, 156), mt_rand(0, 156));
            imageline($this->img, mt_rand(0, $this->width), mt_rand(0, $this->height), mt_rand(0, $this->width), mt_rand(0, $this->height), $color);
        }
        // 雪花
        for ($i = 0; $i < 100; $i ++) {
            $color = imagecolorallocate($this->img, mt_rand(200, 255), mt_rand(200, 255), mt_rand(200, 255));
            imagestring($this->img, mt_rand(1, 5), mt_rand(0, $this->width), mt_rand(0, $this->height), '*', $color);
        }
    }
    // 输出
    private function outPut()
    {
        header('Content-type:image/png');
        imagepng($this->img);
        imagedestroy($this->img);
    }
    // 对外生成
    public function doimg()
    {
        $this->createBg();
        $this->createCode();
        $this->createLine();
        $this->createFont();
        $this->outPut();
    }
    // 获取验证码
    public function getCode()
    {
        return strtolower($this->code);
    }
}
